/* ----------------------------------------------------------------------
* Copyright (C) 2010 ARM Limited. All rights reserved.
*
* $Date:        15. February 2012
* $Revision: 	V1.1.0
*
* Project: 	    CMSIS DSP Library
* Title:	    arm_mat_mult_f32.c
*
* Description:  Floating-point matrix multiplication.
*
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*
* Version 1.1.0 2012/02/15
*    Updated with more optimizations, bug fixes and minor API changes.
*
* Version 1.0.10 2011/7/15
*    Big Endian support added and Merged M0 and M3/M4 Source code.
*
* Version 1.0.3 2010/11/29
*    Re-organized the CMSIS folders and updated documentation.
*
* Version 1.0.2 2010/11/11
*    Documentation updated.
*
* Version 1.0.1 2010/10/05
*    Production release and review comments incorporated.
*
* Version 1.0.0 2010/09/20
*    Production release and review comments incorporated.
*
* Version 0.0.5  2010/04/26
*    incorporated review comments and updated with latest CMSIS layer
*
* Version 0.0.3  2010/03/10
*    Initial version
* -------------------------------------------------------------------- */

#include "arm_math.h"

/**
 * @ingroup groupMatrix
 */

/**
 * @defgroup MatrixMult Matrix Multiplication
 *
 * Multiplies two matrices.
 *
 * \image html MatrixMultiplication.gif "Multiplication of two 3 x 3 matrices"

 * Matrix multiplication is only defined if the number of columns of the
 * first matrix equals the number of rows of the second matrix.
 * Multiplying an <code>M x N</code> matrix with an <code>N x P</code> matrix results
 * in an <code>M x P</code> matrix.
 * When matrix size checking is enabled, the functions check: (1) that the inner dimensions of
 * <code>pSrcA</code> and <code>pSrcB</code> are equal; and (2) that the size of the output
 * matrix equals the outer dimensions of <code>pSrcA</code> and <code>pSrcB</code>.
 */


/**
 * @addtogroup MatrixMult
 * @{
 */

/**
 * @brief Floating-point matrix multiplication.
 * @param[in]       *pSrcA points to the first input matrix structure
 * @param[in]       *pSrcB points to the second input matrix structure
 * @param[out]      *pDst points to output matrix structure
 * @return     		The function returns either
 * <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.
 */

arm_status arm_mat_mult_f32(
    const arm_matrix_instance_f32* pSrcA,
    const arm_matrix_instance_f32* pSrcB,
    arm_matrix_instance_f32* pDst)
{
	float32_t* pIn1 = pSrcA->pData;                /* input data matrix pointer A */
	float32_t* pIn2 = pSrcB->pData;                /* input data matrix pointer B */
	float32_t* pInA = pSrcA->pData;                /* input data matrix pointer A  */
	float32_t* pOut = pDst->pData;                 /* output data matrix pointer */
	float32_t* px;                                 /* Temporary output data matrix pointer */
	float32_t sum;                                 /* Accumulator */
	uint16_t numRowsA = pSrcA->numRows;            /* number of rows of input matrix A */
	uint16_t numColsB = pSrcB->numCols;            /* number of columns of input matrix B */
	uint16_t numColsA = pSrcA->numCols;            /* number of columns of input matrix A */

#ifndef ARM_MATH_CM0

	/* Run the below code for Cortex-M4 and Cortex-M3 */

	float32_t in1, in2, in3, in4;
	uint16_t col, i = 0u, j, row = numRowsA, colCnt;      /* loop counters */
	arm_status status;                             /* status of matrix multiplication */

#ifdef ARM_MATH_MATRIX_CHECK


	/* Check for matrix mismatch condition */
	if((pSrcA->numCols != pSrcB->numRows) ||
	        (pSrcA->numRows != pDst->numRows) || (pSrcB->numCols != pDst->numCols)) {

		/* Set status as ARM_MATH_SIZE_MISMATCH */
		status = ARM_MATH_SIZE_MISMATCH;
	} else
#endif /*      #ifdef ARM_MATH_MATRIX_CHECK    */

	{
		/* The following loop performs the dot-product of each row in pSrcA with each column in pSrcB */
		/* row loop */
		do {
			/* Output pointer is set to starting address of the row being processed */
			px = pOut + i;

			/* For every row wise process, the column loop counter is to be initiated */
			col = numColsB;

			/* For every row wise process, the pIn2 pointer is set
			 ** to the starting address of the pSrcB data */
			pIn2 = pSrcB->pData;

			j = 0u;

			/* column loop */
			do {
				/* Set the variable sum, that acts as accumulator, to zero */
				sum = 0.0f;

				/* Initiate the pointer pIn1 to point to the starting address of the column being processed */
				pIn1 = pInA;

				/* Apply loop unrolling and compute 4 MACs simultaneously. */
				colCnt = numColsA >> 2u;

				/* matrix multiplication        */
				while(colCnt > 0u) {
					/* c(m,n) = a(1,1)*b(1,1) + a(1,2) * b(2,1) + .... + a(m,p)*b(p,n) */
					in3 = *pIn2;
					pIn2 += numColsB;
					in1 = pIn1[0];
					in2 = pIn1[1];
					sum += in1 * in3;
					in4 = *pIn2;
					pIn2 += numColsB;
					sum += in2 * in4;

					in3 = *pIn2;
					pIn2 += numColsB;
					in1 = pIn1[2];
					in2 = pIn1[3];
					sum += in1 * in3;
					in4 = *pIn2;
					pIn2 += numColsB;
					sum += in2 * in4;
					pIn1 += 4u;

					/* Decrement the loop count */
					colCnt--;
				}

				/* If the columns of pSrcA is not a multiple of 4, compute any remaining MACs here.
				 ** No loop unrolling is used. */
				colCnt = numColsA % 0x4u;

				while(colCnt > 0u) {
					/* c(m,n) = a(1,1)*b(1,1) + a(1,2) * b(2,1) + .... + a(m,p)*b(p,n) */
					sum += *pIn1++ * (*pIn2);
					pIn2 += numColsB;

					/* Decrement the loop counter */
					colCnt--;
				}

				/* Store the result in the destination buffer */
				*px++ = sum;

				/* Update the pointer pIn2 to point to the  starting address of the next column */
				j++;
				pIn2 = pSrcB->pData + j;

				/* Decrement the column loop counter */
				col--;

			} while(col > 0u);

#else

	/* Run the below code for Cortex-M0 */

	float32_t* pInB = pSrcB->pData;                /* input data matrix pointer B */
	uint16_t col, i = 0u, row = numRowsA, colCnt;  /* loop counters */
	arm_status status;                             /* status of matrix multiplication */

#ifdef ARM_MATH_MATRIX_CHECK

	/* Check for matrix mismatch condition */
	if((pSrcA->numCols != pSrcB->numRows) ||
	        (pSrcA->numRows != pDst->numRows) || (pSrcB->numCols != pDst->numCols)) {

		/* Set status as ARM_MATH_SIZE_MISMATCH */
		status = ARM_MATH_SIZE_MISMATCH;
	} else
#endif /*      #ifdef ARM_MATH_MATRIX_CHECK    */

	{
		/* The following loop performs the dot-product of each row in pInA with each column in pInB */
		/* row loop */
		do {
			/* Output pointer is set to starting address of the row being processed */
			px = pOut + i;

			/* For every row wise process, the column loop counter is to be initiated */
			col = numColsB;

			/* For every row wise process, the pIn2 pointer is set
			 ** to the starting address of the pSrcB data */
			pIn2 = pSrcB->pData;

			/* column loop */
			do {
				/* Set the variable sum, that acts as accumulator, to zero */
				sum = 0.0f;

				/* Initialize the pointer pIn1 to point to the starting address of the row being processed */
				pIn1 = pInA;

				/* Matrix A columns number of MAC operations are to be performed */
				colCnt = numColsA;

				while(colCnt > 0u) {
					/* c(m,n) = a(1,1)*b(1,1) + a(1,2) * b(2,1) + .... + a(m,p)*b(p,n) */
					sum += *pIn1++ * (*pIn2);
					pIn2 += numColsB;

					/* Decrement the loop counter */
					colCnt--;
				}

				/* Store the result in the destination buffer */
				*px++ = sum;

				/* Decrement the column loop counter */
				col--;

				/* Update the pointer pIn2 to point to the  starting address of the next column */
				pIn2 = pInB + (numColsB - col);

			} while(col > 0u);

#endif /* #ifndef ARM_MATH_CM0 */

			/* Update the pointer pInA to point to the  starting address of the next row */
			i = i + numColsB;
			pInA = pInA + numColsA;

			/* Decrement the row loop counter */
			row--;

		} while(row > 0u);

		/* Set status as ARM_MATH_SUCCESS */
		status = ARM_MATH_SUCCESS;
	}

	/* Return to application */
	return (status);
}

/**
 * @} end of MatrixMult group
 */
